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Behavioral and Transcriptomic Effects of Paroxetine on the Fathead Minnow (Pimephales promales)
Citation:
Bell, M., D. Sullivan, AND W. Huang. Behavioral and Transcriptomic Effects of Paroxetine on the Fathead Minnow (Pimephales promales). SETAC North America, Pittsburgh, PA, November 13 - 17, 2022. https://doi.org/10.23645/epacomptox.21554502
Impact/Purpose:
Poster presented to the Society of Environmental Toxicology and Chemistry (SETAC) annual meeting November 2022. Fathead minnows are a small freshwater species found throughout many aquatic systems in North America, making them an ideal candidate to study toxicological effects of chemical exposure in the ecosystem. Paroxetine is a well-characterized serotonin selective reuptake inhibitor (SSRI) commonly found in surface waters in freshwater systems. Paroxetine is an anti-depressant pharmaceutical that can influence gene expression and behavioral responses. Both unique endpoints will provide insight on how aquatic vertebrates may be impacted to SSRI exposures in the environment. We aimed to analyze the response to paroxetine using movement data as a proxy for behavior, and gene expression data together to make informed conclusions on SSRI exposure.
Description:
Paroxetine (PXT) is an antidepressant serotonin selective reuptake inhibitor (SSRI) and has been frequently detected in surface waters and other environmental matrices in North America. Previous research has indicated the presence of PXT in tissue of fauna inhabiting affected freshwater ecosystems, but little is known of how PXT may influence transcriptional and behavioral response of fish. The fathead minnow (Pimephales promelas, FHM) is a broadly distributed and well-studied small, freshwater fish species, thus making it a good candidate to use as a model for investigating the effects of chemicals in the freshwater environment. PXT alters neurotransmission through inhibiting reabsorption of serotonin in neurons, allowing increased presence of serotonin in signals between nerve cells, therefore we hypothesized that increased levels of serotonin in FHM through PXT exposure would influence behavior and gene expression. Prior research on human consumption of PXT and other SSRIs, has shown that increased serotonin levels may cause side effects of fatigue, dizziness, and slow reaction to stimulants. Because of these side effects, we predicted that increased concentrations of PXT would cause decreased movement in response to photoperiodicity because of increased serotonin levels. Likewise, we predicted that differential gene expression would occur at greater rates with increasing concentrations of PXT. To evaluate how PXT influences gene expression and behavior of FHM, we exposed larval FHM (5 days post fertilization) for 24 hours to ten concentrations of PXT. Larval FHM from all treatments were homogenized to isolate RNA and generate mRNA libraries for sequencing. Concentrations used in evaluation of gene expression ranged from 1.5mg/L to 50ng/L and moderately hard reconstituted water (MHRW) as a control. Behavior assays were performed using larval FHM exposed to control and highest three concentrations (1.5mg/L, 0.5mg/L, and 0.15mg/L) of PXT and were analyzed to evaluate how individuals responded to photoperiodicity. Here, we will present the results of our research and the importance of using unique biological endpoints to evaluate the effects of chemicals that may not be detected using traditional endpoints (mortality, reproduction, growth). Further, we will discuss our findings on how PXT and mechanistically similar SSRIs may have an adverse effect on fauna inhabiting freshwater systems where PXT and SSRIs are found.
URLs/Downloads:
DOI: Behavioral and Transcriptomic Effects of Paroxetine on the Fathead Minnow (Pimephales promales)
SETAC 2022 FINAL POSTER_MBELL.PDF (PDF, NA pp, 603.073 KB, about PDF)